The present invention is related to a locking and unlocking structure for a telescopic tube, in which the daughter tube is firmly locked with the mother tube by means of restricting holes and frictional stop holes of restricting plates and restricting rings with biased axis. Therefore, the daughter tube can be stagelessly adjusted in length and more firmly locked with the mother tube. Moreover, the adjustment device and the adjustment rod are both installed in the daughter and mother tubes so that the appearance of the telescopic tube will not be affected.
FIG. 1 shows a conventional locking and unlocking structure of a telescopic tube. A daughter tube 11 is fitted in a mother tube 10. The outer diameter of the daughter tube 11 is slightly smaller than the inner diameter of the mother tube 10, whereby the daughter tube 11 can be freely moved within the mother tube 10. The circumferential wall of the mother tube 10 is formed with multiple adjustment holes 101 at equal intervals. The rear end of the daughter tube 11 is formed with a through hole 111 in which a V-shaped snap button 112 is mounted. The snap button 112 has a press section 113 protruding out of the through hole 111 of the daughter tube 11 into one of the adjustment holes 101 of the mother tube 10 at a certain length. When adjusted, the press section 113 is pressed inward to disengage from the adjustment hole 101. Under such circumstance, the daughter tube 11 is unlocked and can be freely moved within the mother tube 10 to a certain length. When the press section 113 is again bounded into a certain adjustment hole 101, the daughter tube 11 is again locked with the mother tube 10.
The above structure has a shortcoming as follows: The adjustment holes 101 of the mother tube 10 are arranged at certain intervals so that the daughter tube 11 cannot be stagelessly adjusted. As a result, a user may be unable to adjust the telescopic tube to an optimal length meeting the requirement of the height of the user.
It is therefore a primary object of the present invention to provide an adjustable locking and unlocking structure for a telescopic tube, in which the adjustment structure can be stagelessly adjusted so that a user can have a using length most suitable for the user""s height. Therefore, the telescopic tube can be more conveniently used and the application range is wider.
It is a further object of the present invention to provide the above adjustable locking and unlocking device in which the daughter tube is firmly locked with the mother tube by means of restricting holes and frictional stop holes with biased axis. Therefore, in use or operation, the daughter tube is prevented from retracting into the mother tube. Therefore, the daughter tube is better located by the adjustment device.
It is still a further object of the present invention to provide the above adjustable locking and unlocking device in which the adjustment device and the adjustment rod are both installed and hidden in the daughter tube and mother tube so that the appearance of the telescopic tube will not be affected.
The present invention can be best understood through the following description and accompanying drawings wherein: